Incidence and Predicted Risk Factors of Pressure Ulcers in Surgical

Research ArticleIncidence and Predicted Risk Factors of PressureUlcers in Surgical Patients Experience at a Medical Centerin Taipei Taiwan

Ling Fu Shaw12 Pao-Chu Chang1 Jung-Fen Lee1 Huei-Yu Kung1 and Tao-Hsin Tung34

1 Department of Nursing Taipei Veterans General Hospital Taipei 11220 Taiwan2 Faculty of Nursing School of Nursing Yang-Ming University Taipei 11220 Taiwan3Department of Medical Research and Education Cheng Hsin General Hospital Taipei 11220 Taiwan4 Faculty of Public Health School of Medicine Fu Jen Catholic University Taipei 24205 Taiwan

Correspondence should be addressed to Tao-Hsin Tung ch2876gmailcom

Received 19 March 2014 Revised 3 June 2014 Accepted 3 June 2014 Published 26 June 2014

Academic Editor Giuseppe Valacchi

Copyright copy 2014 Ling Fu Shaw et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Purpose To explore the context of incidence of and associated risk factors for pressure ulcers amongst the population of surgicalpatientsMethods The initial study cohort was conducted with a total of 297 patients admitted to a teaching hospital for a surgicaloperation from November 14th to 27th 2006 in Taipei Taiwan The Braden scale pressure ulcers record sheet and perioperativepatient outcomes free from signs and symptoms of injury related to positioning and related nursing interventions and activitieswere collected Results The incidence of immediate and thirty-minute-later pressure ulcers is 98 (29297) and 51 (15297)respectively Using logistic regression model the statistically significantly associated risk factors related to immediate and thirty-minute-later pressure ulcers include operation age type of anesthesia type of operation position type of surgery admission Bradenscore and number of nursing intervention after adjustment for confounding factors Conclusion Admission Braden score andnumber of nursing intervention are well-established protected factors for the development of pressure ulcers Our study shows thatolder operation age type of anesthesia type of operation position and type of surgery are also associated with the development ofpressure ulcers

1 Introduction

Pressure ulcers are known as bed scores and decubitus ulcersand occur mainly in parts of the body that are subject to highpressure from body weight on bony prominences [1] thusthey have been defined as ldquoan area of unrelieved pressure usu-ally over a bony prominence leading to ischemia cell deathand tissue necrosisrdquo [2]This disease often manifests negativeoutcomes for patients after surgeries which may includepain additional treatment and surgery longer hospital staysdisfigurement or scarring increasedmorbidity and increasedmedical costs [3] The development of pressure ulcer in hos-pitalized patients who have undergone a surgical procedure isalso prompted [2ndash6] In addition pressure ulcers have beendescribed as one of themost costly and physically debilitating

complications in the 20th century [7] Because pressure ulcersremain a major health postsurgery problem identification ofpatients at risk for pressure ulcer development is imperativefor implementing cost-effective evidence-based preventivemeasures Continuous risk assessment could be viewed asthe continuous clinical view and judgment of the patientrsquospressure ulcers risk with the goal of conducing preventivemeasures that meet the particular risk factor

A multidisciplinary method is necessary in pressureprevention and treatment and a large part of the responsibilityfalls on nurses in this approach [5] From the viewpoint ofpreventive medicine it is important to not only be cognizantof the background morbidity of pressure ulcers regionallybut also explore the complete spectrum of demographic andbiological markers which may be related to the development

Hindawi Publishing CorporationBioMed Research InternationalVolume 2014 Article ID 416896 9 pageshttpdxdoiorg1011552014416896

2 BioMed Research International

of pressure ulcers Although numerous studies focusing onmorbidity and risk factors of pressure ulcers have beenconducted in western countries [6ndash9] to the best of ourknowledge however such studies are limitedmdashfew nationalor local databases of surgical patientsrsquo records regarding pres-sure ulcers morbidity are found in Taiwan It is essential toidentify patients at risk and to plan appropriate interventionsto prevent the development of pressure ulcers [5] In orderto improve the quality of care for patients with surgicaloperation it is necessary for the healthcare professionalsin Taiwan to acquire knowledge of the risks for pressureulcers development and clinical risk factors and furtherpreventive measurement pertaining to pressure ulcers is alsonecessary Nurses are also responsible in the places theywork for identifying patients at risk for pressure ulcers andfor carrying out the pressure ulcer preventive measures [5]This study is designed to explore the potential perioperativefactors and related nursing interventions and activities thento improve the understanding of the overall pathogenesisof pressure ulcers The purpose of this study is to explorethe context of immediate and thirty-minute-later incidenceof and associated risk factors for pressure ulcers amongstthe population of surgical patient as determined by theapplication of the subjectsrsquo study program at a fully certifiedmedical center and teaching hospital in Taipei Taiwan

2 Methods

21 Study Design and Sample Selection This study was con-ducted in a medical center in Northern Taiwan The researchsample included patients who agreed to participate whowere 18 years old or older who were able to communicatein either Mandarin or Taiwanese having had a first timeelective surgery and a surgical procedure lasting more than30 minutes under spinal or general anaesthesia and whohad neither existing pressure ulcers nor any traumas beforesurgery The study spanned from November 14th to 27th2006 Patients were enrolled from the medical specialismsof cardiovascular general surgery chest surgery orthopedicsurgery neurosurgery plastic surgery and urologic surgeryThe investigation was of an observational follow-up studydesign and therefore the study sample selected all patientswho were listed on the surgical elective schedule during theresearch period Finally a total of 297 patients agreed toparticipate in the study Table 4 shows the study flowchartof the recruitment Written permission was obtained fromthe study institution and managements that were involvedInformed consents in this study were obtained verbally fromthe patients prior to surgery The surgeons and perioperativenurses of the operating room were also informed aboutthe procedure of the study All procedures were performedin accordance with the guidelines of ethics and adheredto the tenets of the Declaration of Helsinki All subjectsrsquoinformation remained anonymous and was only used foranalytical purposes

22 Data Collection Data were collected by using structuredquestionnaires including The Braden Pressure Ulcer Risk

Assessment scale (a summated rating scale made up of sixsubscales scored from 1 to 3 or 4 for total scores thatrange from 6 to 23 a lower Braden scale score indicatesa lower level of functioning and therefore a higher levelof risk for pressure ulcer development) [10] pressure ulcersrecord sheet perioperative patient outcomes free from signsand symptoms of injury related to positioning and relatednursing interventions and activities operation time type ofanesthesia and surgical positioning body temperature andblood pressure occurrence of shear power and wetness dur-ing operation and use of heart-lung machine Demographiccharacteristics such as gender age bodymass index personalpast diseases and nutrition were assessed preoperatively byperioperative nurse leaders The type of anesthesia and sur-gical positioning use of heart-lung machine measurementof blood pressure during operation and the occurrence ofshear power and wetness were collected intraoperativelyBody temperature was observed immediately after surgicaloperation

Pressure ulcers were defined by the National PressureUlcer Advisory Panel (NPUAP) and European PressureUlcerAdvisory Panel (EPUAP) as ldquolocalized injury to the skinandor underlying tissue usually over a bony prominence asa result of pressure or pressure in combination with shearandor frictionrdquo [2 11] In this study the perioperative nurseleaders and nurses of the operating room and postanes-thesia recovery room who participated in the study wereinformed about the study design and received a pressureulcer assessment evaluation tests The occurrence of thepressure ulcer was observed both immediately after operationin the operating room and 30 minutes postoperatively inthe postanesthesia recovery room The thirty-eight nursinginterventions and activities were also recorded [12] Thisstudy selected one perioperative outcome ldquopatient is free fromsigns and symptoms of injury related to positioningrdquo andrelated nursing interventions from the development of anoutcome-oriented perioperative nursing data set in TaiwanrdquoThe content validation was ascertained via expert validityand the inclusion criteria were set at a CVI larger than 080in addition the CVI of above selected thirty-eight nursingintervention items was 10 In addition in order to set up aconsistent diagnosis of pretest and posttest pressure ulcersthe results of the test and retest reliability were examined bypaired 119905-test (119905 = 119 119875 lt 00001) that is the study nursesdemonstrate accuracy of the data collection for pressureulcers

23 Statistical Analysis The statistical analysis was per-formed using SAS 91 (SAS Institute Cary NC USA) Inthe univariate analysis the 1205942-test and independent 119905-testmethod were adopted to assess the differences of the meanvalue of categorical and continuous variables respectivelyThe logistic regression model was used to assess the effectsof relevant factors on each type of pressure ulcer afteradjustment for the covariates Odds ratio (OR) and 95confidence interval (CI) were used for the independent effectof associated variables A 119875 value of lt005 was consideredstatistically significant

BioMed Research International 3

Table 1 The gender specific information of study patients (119899 = 297)

VariablesFemale (119899 = 135)Number ()or mean plusmn SD

Male (119899 = 162)Number ()or mean plusmn SD

Total (119899 = 297)Number ()or mean plusmn SD

119875 value for 1205942-testor 119905-test

Categorical variablesPast disease

Yes 94 (696) 122 (753) 216 (727) 027No 41 (304) 40 (247) 81 (273)

SmokingYes 9 (67) 46 (284) 55 (186)

lt00001No 126 (933) 116 (716) 241 (814)

Type of anesthesia (generalanesthesia)

Yes 99 (733) 99 (611) 198 (667) 003No 36 (267) 63 (389) 99 (333)

Type of operation positionSupine 88 (652) 94 (580) 182 (613)

017Prone 18 (133) 19 (117) 37 (125)Lithotomy 12 (89) 29 (179) 41 (138)Lateral 13 (96) 18 (111) 31 (104)Others 4 (30) 2 (12) 6 (20)

Type of surgeryGeneral surgery 64 (474) 91 (562) 155 (522)

003Neurosurgery 13 (96) 11 (68) 24 (81)Orthopedics surgery 52 (385) 42 (259) 94 (317)Cardiac surgery 6 (44) 18 (111) 24 (81)

Warmer usedYes 107 (793) 135 (833) 242 (815) 037No 28 (207) 27 (167) 55 (185)

ShearYes 67 (496) 80 (494) 147 (495) 097No 68 (504) 82 (506) 150 (505)

WetYes 4 (30) 12 (74) 16 (54) 009No 131 (970) 150 (926) 281 (946)

Heart-lung machine usedYes 4 (30) 6 (37) 10 (34) 072No 131 (970) 156 (963) 287 (966)

Diastolic blood pressure less than60mmHg during operation

Yes 104 (770) 111 (685) 215 (724) 010No 31 (230) 51 (315) 82 (276)

Continuous variablesOperation age (yrs) 599 plusmn 145 649 plusmn 154 626 plusmn 152 0004Body mass index (Kgm2) 248 plusmn 44 250 plusmn 36 249 plusmn 40 076Hemoglobin (gdL) 132 plusmn 68 137 plusmn 53 134 plusmn 60 048Hematocrit () 369 plusmn 55 386 plusmn 65 378 plusmn 61 002Admission Braden score 217 plusmn 24 216 plusmn 23 217 plusmn 23 072


Table 1 Continued





Time of operation (min) 1974 plusmn 1115 2108 plusmn 1456 2047 plusmn 1311 038Number of nursing intervention 359 plusmn 82 364 plusmn 79 362 plusmn 80 065Ear temperature after operation (∘C) 359 plusmn 08 359 plusmn 09 359 plusmn 09 057Total time of diastolic bloodpressure less than 60mmHg (min) 838 plusmn 944 711 plusmn 1005 769 plusmn 978 027

3 Results

The gender specific information of the 297 study patients isshown in Table 1 The distribution of smokers (female 67male 284 119875 lt 00001) type of anesthesia (female 733male 611119875 = 003) type of general surgery (female 474male 562 119875 = 003) operation age (female 599 plusmn 145male 649 plusmn 154 119875 = 0004) and hematocrit (female 369 plusmn55 male 386 plusmn 65 119875 = 002) had statistical significantdifference between male and female

As Table 2 shows there are 29 and 15 patients who werediagnosed as stage I immediate and thirty-minute-later pres-sure ulcer The incidence of immediate and thirty-minute-later pressure ulcer is 98 (29297) and 51 (15297) respec-tively Type of anesthesia (OR = 1614 95 CI 216ndash12047)type of operation position (prone versus supine OR = 629895 CI 1698ndash23355 lateral versus supine OR = 1432 95CI 337ndash6091) type of surgery (orthopedics surgery versusgeneral surgeryOR= 588 95CI 224ndash1543) operation age(OR= 103 95CI 100ndash106) admissionBraden score (OR=085 95CI 075ndash097) and number of nursing intervention(OR = 095 95 CI 089ndash099) are significantly relevantto immediate pressure ulcers In addition the significantrisk factors related to pressure ulcers of 30 minutes laterincluded type of anesthesia (OR = 745 95 CI 100ndash5751)type of operation position (prone versus supine OR = 221095 CI 572ndash8543) type of surgery (orthopedics surgeryversus general surgery OR = 1833 95 CI 231ndash14569cardiac surgery versus general surgery OR = 2200 95 CI219ndash22134) heart-lung machine used (OR = 527 95 CI102ndash2734) operation age (OR = 104 95 CI 100ndash109)admission Braden score (OR = 084 95 CI 071ndash098)and number of nursing intervention (OR = 094 95 CI090ndash098)

The effects of independent associated factors of eachtype of pressure ulcers are examined by the multiple logisticregression model in Table 3 The statistically significantlyassociated risk factors related to immediate pressure ulcerinclude operation age (OR = 103 95 CI 100ndash108) typeof anesthesia (general anesthesia) (yes versus no OR = 170695 CI 209ndash4943) type of operation position (nonsupineversus supine OR = 3226 95 CI 448ndash4879) type ofsurgery (orthopedics surgery versus general surgery OR =333 95 CI 105ndash1061) admission Braden score (OR =095 95CI 091ndash099) and number of nursing intervention(OR = 094 95 CI 090ndash098) Operation age (OR = 10695 CI 100ndash112) type of operation position (nonsupine

versus supine OR = 1818 95 CI 132ndash5263) type ofsurgery (orthopedics surgery versus general surgery OR =929 95 CI 105ndash2850 cardiac surgery versus generalsurgery OR = 2260 95 CI 120ndash4385) and number ofnursing intervention (OR = 095 95 CI 091ndash099) areindependently significant relevant to pressure ulcers of 30minutes later after adjustment for confounding factors

4 Discussion

41 Morbidity of Pressure Ulcer Previous studies focusedon nonblanchable erythema as the early identification ofpressure ulcer and investigated the factors for developing intomore severe pressure ulcers [13] In this study the reasons forevaluating pressure ulcer at two points of time were becauseblanchable erythema is the first clinical sign of pressure ulcerdevelopment especially over a bony prominent area aftersurgery Incidence of blanchable erythema and deteriorationto pressure ulcer were reported on surgical patients [13]Postoperative patients routinely stayed in the postanesthesiarecovery room for at least two hours unmoved blanchableerythema could worsen to pressure ulcer of either stage I orII Detecting the blanchable erythema is expected to provideappropriate care to prevent pressure ulcer

Early detection of pressure ulcer has been emphasizedbecause it could prevent skin alteration from progressingto skin loss Patients are exposed to complications duringsurgical operations for reasons associated with the surgicalposition and for many other causes It is known that pressureulcers are lesions caused by unrelieved pressure that resultsin damage to the underlying tissue This disorder is a healthproblem that brings both high material and emotional lossesto patients [5] Generally these are the results of soft tissuecompression between a bony prominence and an externalsurface for a prolonged period of time [14] Knowledge ofpressure ulcer epidemiology is therefore crucial in managingthis disorder not only for planning preventive programs butalso for the identification of the best therapeutic strategyThe incidence of pressure ulcer amongst different test pop-ulations appears to vary differing among different studiesconducted in different countries In this study the incidenceof immediate and thirty-minute-later pressure ulcers is 98and 51 respectively Incidence rates of pressure ulcers aslow as 04 to as high as 38 have been reported in theinpatient department while prevalence has been reported as35 to 69 [2 8 9 15ndash17] In long-term care facilities


Table 2 Univariate analysis for comparison of characteristics in pressure ulcers among study population (119899 = 297)

Types of pressure ulcersImmediately 30 minutes later

Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)

Categorical variablesGender

Female 13 122 097 5 130 059Male 16 146 (045ndash210) 10 152 (020ndash175)

Past diseaseYes 21 195 098 11 205 103No 8 73 (042ndash232) 4 77 (032ndash334)

SmokingYes 4 51 068 3 52 111No 25 217 (023ndash204) 12 230 (030ndash406)


Yes 28 170 1614 14 184 745No 1 98 (216ndash12047) 1 98 (100ndash5751)

Type of operation positionSupine 3 179 100 3 179 100Prone 19 18 6298 (1698ndash23355) 10 27 2210 (572ndash8543)Lithotomy 1 40 149 (015ndash1472) 0 41 mdashLateral 6 25 1432 (337ndash6091) 2 29 411 (066ndash2570)Others 0 6 mdash 0 6 mdash

Type of surgeryGeneral surgery 6 149 100 1 154 100Neurosurgery 2 22 225 (043ndash1189) 1 23 670 (040ndash11079)Orthopedics surgery 18 76 588 (224ndash1543) 10 84 1833 (231ndash14569)Cardiac surgery 3 21 355 (082ndash1526) 3 21 2200 (219ndash22134)

Warmer usedYes 28 214 706 15 227 mdashNo 1 54 (094ndash5304) 0 55

ShearYes 12 135 070 6 141 067No 17 133 (032ndash151) 9 141 (023ndash192)

WetYes 1 15 060 0 16 mdashNo 28 253 (008ndash473) 15 266

Heart-lung machine usedYes 2 8 241 2 8 527No 27 260 (049ndash1192) 13 274 (102ndash2734)

Diastolic blood pressureless than 60mmHg duringoperation



Table 2 Continued


Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)

Continuous variablesAge (yrs) mdash 103 (100ndash106) mdash 104 (100ndash109)Body mass index (Kgm2) mdash 103 (093ndash113) mdash 100 (087ndash114)Hemoglobin (gdL) mdash 099 (092ndash107) mdash 099 (089ndash110)Hematocrit () mdash 099 (093ndash105) mdash 104 (095ndash114)Admission Braden score mdash 085 (075ndash097) mdash 084 (071ndash098)Time of operation (min) mdash 100 (098ndash102) mdash 100 (099ndash101)Number of nursingintervention mdash 095 (089ndash099) mdash 094 (090ndash098)

Ear temperature afteroperation mdash 093 (060ndash144) mdash 077 (043ndash138)

Total time of diastolicblood pressure less than60mmHg (min)

mdash 100 (099ndash101) mdash 100 (099ndash102)

Table 3 Multivariate analysis using logistic regression model of risk factors associated with the pressure ulcers among study population(119899 = 297)

VariableTypes of pressure ulcers (yes versus no)

Immediately 30 minutes laterOR (95 CI) OR (95 CI)

Gender (female versus male) 098 039ndash261 065 018ndash227Operation age (yrs) 103 100ndash108 106 100ndash112Type of anesthesia (general anesthesia) (yes versus no) 1706 209ndash4943 529 056ndash4671Type of operation position (nonsupine versus supine) 3226 448ndash4879 1818 132ndash5263Type of surgery

General surgery 100 mdash 100 mdashNeurosurgery 129 020ndash858 557 028ndash1969Orthopedics surgery 333 105ndash1061 929 105ndash2850Cardiac surgery 698 072ndash3988 2260 120ndash4385

Heart-lung machine used (yes versus no) 524 051ndash4355 758 051ndash4928Admission Braden score 095 091ndash099 093 080ndash109Number of nursing intervention 094 090ndash098 095 091ndash099The Hosmer-Lemeshow test 120594

2

(8)= 379 119875 = 088 120594

2

(8)= 417 119875 = 084

c-statistics 0914 0917

the reported incidence is between 22 and 239 whilein home care setting the incidence varies from 0 to 17[15] Many trials have chosen not to include them sincethey are difficult to be reliably detected although stage 1ulcers are frequently encountered [18] Further well-designedepidemiological investigations of pressure ulcers in varioussettings are still required In addition not surprisingly thehospital stay is longer in pressure ulcer patients with bothexcess likelihood of nosocomial renal infections and thehospital readmission rate A previous study based on thehospital billing codes also revealed an increase in the numberof hospital stays involving pressure ulcers by nearly 80 [19]This implies that pressure ulcers result in an exponential

increase in the healthcare burden and financial requirementfor these patients

42 Implications as Regards Associated Risk Factors for Pres-sure Ulcer In Taiwan one study on elective surgical patientrevealed that the incidence of the perioperative pressureulcer in surgical patients was 70 and the significantfactors associated with pressure ulcer development were agepreoperative chronic cerebral arterial disease preoperativeBMI total protein level albumin level Braden scale scoresoperative time body temperature and intraoperative bloodpressure [12] Previous study also indicated that preopera-tively all patients carry a risk for pressure ulcers that risk


Table 4 The study flowchart of the recruitment

Preoperative119873 = 297 Intraoperative119873 = 297 Postoperative119873 = 297

The day before operation Operation day whenarrived in holding area

Operation day duringprocedure

Operation day inpostanesthesia recoveryroom

Selected patients fromnext dayrsquos electivesurgical scheduleincluded patients who(1) agreed to participate(2) have a first timeelective surgery(3) have procedurelasting more than 30minutes(4) are under spinal orgeneral anesthesia and(5) have no existingpressure ulcers nor anytraumas before surgery

Assessment of(1) the Braden scale and(2) patient demographiccharacteristics and healthstatus

997888997888rarr

Assessment of(1) pressure ulcers recordsheet(2) related nursinginterventions and activitiesand(3) operation related dataoperation time type ofanesthesia positioningbody temperature and soforth

997888997888rarr

Assessment of(1) pressure ulcers recordsheet and(2) related evaluation to thenursing interventions andactivities

postoperatively and that it is necessary to use a measureof risk to identify patientsrsquo risk for surgery-related pressureulcer [5 20] In this study none of the preoperative physicalcondition (ie past disease hemoglobin hematocrit andsmoking habit) nutrition (ie BMI and albumin) andintraoperative status (time of the operation total time ofdiastolic blood pressure less than 60mmHg application ofheart-lung machine body temperature after procedure andshear power and wetness) variables measured emerged asstatistically significant risk factors for pressure ulcer devel-opment It is possible that the control of the patient physicalcondition such as blood pressure and body temperature wassatisfactory anddid not affect the development of the pressureulcer And this also may be related to adequate preventivenursing interventions performed perioperatively

The estimated incidence of pressure ulcers increased withoperation age in this study Such a finding is consistent withresults of other studies conducted elsewhere [21] It meansthat the long-term exposure tomany other risk factors amongelder persons may also account for the increased probabilityof developing pressure ulcers In addition the reduced risksfor pressure ulcers found in relation to admission Bradenscore increased The Braden Pressure Ulcer Risk Assessmentscale was developed by Barbara Braden in 1987 and there havebeen many studies in the US and UK which have shown itsvalidity and reliability [1 5 21] In the determination of riskpreoperatively and postoperatively with the Braden PressureUlcer Risk Assessment scale that was used in this studyand in the determination of areas at risk [5] it could offerdetailed clues for planning appropriate patient interventionsfor pressure ulcers

Our results also support the hypothesis that the numberof nursing interventions is at lower risk for developmentof pressure ulcers The result of the study will improveperioperative nursing and provide the nursing administratorswith the effects of the clinical perioperative nursing forthe pressure ulcers prevention A multidisciplinary approach

is essential in prevention of pressure ulcers and a largepart of the responsibility falls on nurses in this approachNursing staff are responsible in the institute they work in foridentifying patients at risk for pressure ulcers and carryingout the preventive measures [5] ldquoPrevention is better thancurerdquo is best emphasized in the case of pressure ulcers Thiscondition is absolutely preventable with care compassionand dedication towards the care of patients Prevention isdirected towards taking care of the extrinsic and intrinsicfactors [2]

The variables including position general anesthesia andtype of surgery had a statistically significant association withincident pressure ulcers in this study Evidence was foundthat the chance of a patient who used general anesthesia topresent pressure ulcers is 48 times greater than that who usedlocal anesthesia (119875 = 0024) It is certain that this correlationis also associated with surgery duration and size as longersurgeries usuallymake use of general anesthesia [22] It pointsat general anesthesia as a factor predisposing the occurrenceof pressure ulcers due to immobilization and absence of skinsensitivity in addition to changes in blood pressure tissueperfusion the patientrsquos response to pain and the oxygenand carbon dioxide exchange [3 22] In addition it shouldbe noted that neurosurgeries in the ventral position includespinal surgeries and this could have determined the higherpressure ulcers incidence observed [22] This hypothesis isalso supported by a study that found a higher pressure ulcersincidence in patients submitted to spinal surgeries [23]

43Methodological Considerations Although using a follow-up study design could clarify the temporal relationship ofpotential risk factors for the development of pressure ulcerthere are some drawbacks in this study A major limitationwas the potential self-selection bias due to the hospital-basedstudy design it is not entirely representative of the wholegeneral population Secondly a logistic regression of a binaryresponse variable (119884) on a binary independent variable (119883)


with a sample size of 297 observations (of which 60 are inthe group 119883 = 0 and 40 are in the group 119883 = 1) achieves74 power at a 005 significance level to detect a change inProb (119884 = 1) from the baseline value of 0097 to 0212 Thischange corresponds to an odds ratio of 2500 An adjustmentwas made since a multiple regression of the independentvariable of interest on the other independent variables inthe logistic regression obtained an 119877-squared of 0100 in thisstudy [24] Although the identifications of pressure ulcersbased on clinician-researchers directly examined patientsmeant estimates are accurate the sample sizes tend to berelatively small and involve only a single facility making gen-eralizability uncertain such that the type of anesthesia hadbroad confidence interval possibly due to the small numberof local anesthesia Thirdly we only observed immediate andthirty-minute-later pressure ulcers There is a possibility thatthey may have been affected by postoperative risk factorsbecause some of the pressure ulcers were seen after thethird postoperative day [5] The true incidence of pressureulcers would be underestimated Further long-term studiesshould be conducted with a larger sample size to explore themorbidity and consequences of pressure ulcers and plausiblebiological mechanisms underlying its development

5 Conclusion

In conclusion admission Braden score and number of nurs-ing intervention are well-established protected factor for thedevelopment of pressure ulcers Our study shows that olderoperation age type of anesthesia type of operation positionand type of surgery are also associated with the developmentof pressure ulcers

Conflict of Interests

We certify that within the past 5 years and foreseeablefuture all our affiliations with or financial involvement in anyorganization or entity with a financial interest in or financialconflict with the subject matter or materials discussed inthe paper (eg employment consultancies honoraria stockownership or options expert testimony grants or patentsreceived or pending and royalties) are completely disclosed

Acknowledgment

This study was supported by the Grants from the TaipeiVeterans General Hospital Taipei Taiwan (V95A-140)

References

[1] O Uzun and M Tan ldquoA prospective descriptive pressure ulcerrisk factor and prevalence study at a university hospital inTurkeyrdquo Ostomy Wound Management vol 53 no 2 pp 44ndash562007

[2] K Agrawal and N Chauhan ldquoPressure ulcers back to thebasicsrdquo Indian Journal of Plastic Surgery vol 45 no 2 pp 244ndash254 2012

[3] A Schultz ldquoPredicting and preventing pressure ulcers in surgi-cal patientsrdquo AORN Journal vol 81 no 5 pp 985ndash1006 2005

[4] R M Allman ldquoPressure ulcer prevalence incidence riskfactors and impactrdquo Clinics in Geriatric Medicine vol 13 no3 pp 421ndash436 1997

[5] M Karadag and N Gumuskaya ldquoThe incidence of pressureulcers in surgical patients a sample hospital in Turkeyrdquo Journalof Clinical Nursing vol 15 no 4 pp 413ndash421 2006

[6] L Gunningberg ldquoRisk prevalence and prevention of pressureulcers in three Swedish healthcare settingsrdquo Journal of WoundCare vol 13 no 7 pp 286ndash290 2004

[7] S R Burdette-Taylor and J Kass ldquoHeel ulcers in criticalcare units a major pressure problemrdquo Critical Care NursingQuarterly vol 25 no 2 pp 41ndash53 2002

[8] E S M Shahin T Dassen and R J G Halfens ldquoIncidenceprevention and treatment of pressure ulcers in intensive carepatients a longitudinal studyrdquo International Journal of NursingStudies vol 46 no 4 pp 413ndash421 2009

[9] B Leblebici N Turhan M Adam and M N Akman ldquoClinicaland epidemiologic evaluation of pressure ulcers in patients ata university hospital in Turkeyrdquo Journal of Wound Ostomy andContinence Nursing vol 34 no 4 pp 407ndash411 2007

[10] J Cox ldquoPredictive power of the braden scale for pressure sorerisk in adult critical care patients a comprehensive reviewrdquoJournal of Wound Ostomy and Continence Nursing vol 39 no6 pp 613ndash621 2012

[11] National Pressure Ulcer Advisory Pane Pressure Ulcers Inci-dence Economics Risk Assessment Consensus DevelopmentConference Statement S-N Publications West Dundee IllUSA 1989 httpwwwnpuaporgpr2htm

[12] F L Shaw H Pan Y J Lu et al ldquoDevelopment of an outcome-oriented perioperative nursing data set in Taiwanrdquo VeteransGeneral Hospital Nursing vol 22 no 4 pp 329ndash338 2005

[13] C Konishi J Sugama H Sanada et al ldquoA prospective studyof blanchable erythema among university hospital patientsrdquoInternational Wound Journal vol 5 no 3 pp 470ndash475 2008

[14] D RThomas ldquoThe new F-tag 314 prevention andmanagementof pressure ulcersrdquo Journal of the American Medical DirectorsAssociation vol 7 no 8 pp 523ndash531 2006

[15] J Cuddigan E A Ayello C Sussman and S Baranoski ldquoPres-sure ulcers in America prevalence incidence and implicationsfor the future An executive summary of the National PressureUlcer Advisory Panel monographrdquo Advances in Skin amp WoundCare vol 14 no 4 pp 208ndash215 2001

[16] M Meehan ldquoMultisite pressure ulcer prevalence surveyrdquoDecu-bitus vol 3 no 4 pp 14ndash17 1990

[17] D G Inan andGOztunc ldquoPressure ulcer prevalence in Turkeya sample from a university hospitalrdquo Journal of Wound Ostomyand Continence Nursing vol 39 no 4 pp 409ndash413 2012

[18] ldquoPressure ulcers prevalence cost and risk assessment consen-sus development conference statementmdashthe National PressureUlcer Advisory Panelrdquo Decubitus vol 2 no 2 pp 24ndash28 1989

[19] C A Russo C Steiner and W Spector HospitalizationsRelated to Pressure Ulcers among Adults 18 Years andOlder 2006 HCUP Statistical Brief 64 Agency forHealthcare Research and Quality Rockville Md USA 2008httpwwwhcup-usahrqgovreportsstatbriefssb64pdf

[20] D Armstrong and P Bortz ldquoAn integrative review of pressurerelief in surgical patientsrdquoAORN Journal vol 73 no 3 pp 645ndash650 2001

[21] M F Cremasco F Wenzel S S Zanei and I Y WhitakerldquoPressure ulcers in the intensive care unit the relationshipbetween nursing workload illness severity and pressure ulcer


riskrdquo Journal of Clinical Nursing vol 22 no 15-16 pp 2183ndash21912013

[22] K C Scarlatti J L Michel M A Gamba and M G deGutierrez ldquoPressure ulcers in surgery patients incidence andassociated factorsrdquo Revista da Escola de Enfermagem da USPvol 45 no 6 pp 1372ndash1379 2011

[23] H Sanada T Nagakawa M Yamamoto K Higashidani HTsuru and J Sugama ldquoThe role of skin blood flow in pressureulcer development during surgeryrdquo Advances in Wound Carevol 10 no 6 pp 29ndash34 1997

[24] F Y Hsieh D A Block and M D Larsen ldquoA simple methodof sample size calculation for linear and logistic regressionrdquoStatistics in Medicine vol 17 no 14 pp 1623ndash1634 1998

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Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom


of pressure ulcers Although numerous studies focusing onmorbidity and risk factors of pressure ulcers have beenconducted in western countries [6ndash9] to the best of ourknowledge however such studies are limitedmdashfew nationalor local databases of surgical patientsrsquo records regarding pres-sure ulcers morbidity are found in Taiwan It is essential toidentify patients at risk and to plan appropriate interventionsto prevent the development of pressure ulcers [5] In orderto improve the quality of care for patients with surgicaloperation it is necessary for the healthcare professionalsin Taiwan to acquire knowledge of the risks for pressureulcers development and clinical risk factors and furtherpreventive measurement pertaining to pressure ulcers is alsonecessary Nurses are also responsible in the places theywork for identifying patients at risk for pressure ulcers andfor carrying out the pressure ulcer preventive measures [5]This study is designed to explore the potential perioperativefactors and related nursing interventions and activities thento improve the understanding of the overall pathogenesisof pressure ulcers The purpose of this study is to explorethe context of immediate and thirty-minute-later incidenceof and associated risk factors for pressure ulcers amongstthe population of surgical patient as determined by theapplication of the subjectsrsquo study program at a fully certifiedmedical center and teaching hospital in Taipei Taiwan

2 Methods

21 Study Design and Sample Selection This study was con-ducted in a medical center in Northern Taiwan The researchsample included patients who agreed to participate whowere 18 years old or older who were able to communicatein either Mandarin or Taiwanese having had a first timeelective surgery and a surgical procedure lasting more than30 minutes under spinal or general anaesthesia and whohad neither existing pressure ulcers nor any traumas beforesurgery The study spanned from November 14th to 27th2006 Patients were enrolled from the medical specialismsof cardiovascular general surgery chest surgery orthopedicsurgery neurosurgery plastic surgery and urologic surgeryThe investigation was of an observational follow-up studydesign and therefore the study sample selected all patientswho were listed on the surgical elective schedule during theresearch period Finally a total of 297 patients agreed toparticipate in the study Table 4 shows the study flowchartof the recruitment Written permission was obtained fromthe study institution and managements that were involvedInformed consents in this study were obtained verbally fromthe patients prior to surgery The surgeons and perioperativenurses of the operating room were also informed aboutthe procedure of the study All procedures were performedin accordance with the guidelines of ethics and adheredto the tenets of the Declaration of Helsinki All subjectsrsquoinformation remained anonymous and was only used foranalytical purposes

22 Data Collection Data were collected by using structuredquestionnaires including The Braden Pressure Ulcer Risk

Assessment scale (a summated rating scale made up of sixsubscales scored from 1 to 3 or 4 for total scores thatrange from 6 to 23 a lower Braden scale score indicatesa lower level of functioning and therefore a higher levelof risk for pressure ulcer development) [10] pressure ulcersrecord sheet perioperative patient outcomes free from signsand symptoms of injury related to positioning and relatednursing interventions and activities operation time type ofanesthesia and surgical positioning body temperature andblood pressure occurrence of shear power and wetness dur-ing operation and use of heart-lung machine Demographiccharacteristics such as gender age bodymass index personalpast diseases and nutrition were assessed preoperatively byperioperative nurse leaders The type of anesthesia and sur-gical positioning use of heart-lung machine measurementof blood pressure during operation and the occurrence ofshear power and wetness were collected intraoperativelyBody temperature was observed immediately after surgicaloperation

Pressure ulcers were defined by the National PressureUlcer Advisory Panel (NPUAP) and European PressureUlcerAdvisory Panel (EPUAP) as ldquolocalized injury to the skinandor underlying tissue usually over a bony prominence asa result of pressure or pressure in combination with shearandor frictionrdquo [2 11] In this study the perioperative nurseleaders and nurses of the operating room and postanes-thesia recovery room who participated in the study wereinformed about the study design and received a pressureulcer assessment evaluation tests The occurrence of thepressure ulcer was observed both immediately after operationin the operating room and 30 minutes postoperatively inthe postanesthesia recovery room The thirty-eight nursinginterventions and activities were also recorded [12] Thisstudy selected one perioperative outcome ldquopatient is free fromsigns and symptoms of injury related to positioningrdquo andrelated nursing interventions from the development of anoutcome-oriented perioperative nursing data set in TaiwanrdquoThe content validation was ascertained via expert validityand the inclusion criteria were set at a CVI larger than 080in addition the CVI of above selected thirty-eight nursingintervention items was 10 In addition in order to set up aconsistent diagnosis of pretest and posttest pressure ulcersthe results of the test and retest reliability were examined bypaired 119905-test (119905 = 119 119875 lt 00001) that is the study nursesdemonstrate accuracy of the data collection for pressureulcers

23 Statistical Analysis The statistical analysis was per-formed using SAS 91 (SAS Institute Cary NC USA) Inthe univariate analysis the 1205942-test and independent 119905-testmethod were adopted to assess the differences of the meanvalue of categorical and continuous variables respectivelyThe logistic regression model was used to assess the effectsof relevant factors on each type of pressure ulcer afteradjustment for the covariates Odds ratio (OR) and 95confidence interval (CI) were used for the independent effectof associated variables A 119875 value of lt005 was consideredstatistically significant








Yes 94 (696) 122 (753) 216 (727) 027No 41 (304) 40 (247) 81 (273)

SmokingYes 9 (67) 46 (284) 55 (186)

lt00001No 126 (933) 116 (716) 241 (814)


Yes 99 (733) 99 (611) 198 (667) 003No 36 (267) 63 (389) 99 (333)






ShearYes 67 (496) 80 (494) 147 (495) 097No 68 (504) 82 (506) 150 (505)

WetYes 4 (30) 12 (74) 16 (54) 009No 131 (970) 150 (926) 281 (946)



Yes 104 (770) 111 (685) 215 (724) 010No 31 (230) 51 (315) 82 (276)



Table 1 Continued






3 Results





4 Discussion






Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)
















Table 2 Continued


Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)











2

(8)= 379 119875 = 088 120594

2

(8)= 417 119875 = 084













997888997888rarr


997888997888rarr










5 Conclusion




Acknowledgment


References
































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of























Yes 94 (696) 122 (753) 216 (727) 027No 41 (304) 40 (247) 81 (273)

SmokingYes 9 (67) 46 (284) 55 (186)

lt00001No 126 (933) 116 (716) 241 (814)


Yes 99 (733) 99 (611) 198 (667) 003No 36 (267) 63 (389) 99 (333)






ShearYes 67 (496) 80 (494) 147 (495) 097No 68 (504) 82 (506) 150 (505)

WetYes 4 (30) 12 (74) 16 (54) 009No 131 (970) 150 (926) 281 (946)



Yes 104 (770) 111 (685) 215 (724) 010No 31 (230) 51 (315) 82 (276)



Table 1 Continued






3 Results





4 Discussion






Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)
















Table 2 Continued


Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)











2

(8)= 379 119875 = 088 120594

2

(8)= 417 119875 = 084













997888997888rarr


997888997888rarr










5 Conclusion




Acknowledgment


References
































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















Table 1 Continued






3 Results





4 Discussion






Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)
















Table 2 Continued


Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)











2

(8)= 379 119875 = 088 120594

2

(8)= 417 119875 = 084













997888997888rarr


997888997888rarr










5 Conclusion




Acknowledgment


References
































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of



















Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)
















Table 2 Continued


Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)











2

(8)= 379 119875 = 088 120594

2

(8)= 417 119875 = 084













997888997888rarr


997888997888rarr










5 Conclusion




Acknowledgment


References
































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















Table 2 Continued


Yes(119899 = 29)

No(119899 = 268) OR (95 CI) Yes

(119899 = 15)No

(119899 = 282) OR (95 CI)











2

(8)= 379 119875 = 088 120594

2

(8)= 417 119875 = 084













997888997888rarr


997888997888rarr










5 Conclusion




Acknowledgment


References
































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of
























997888997888rarr


997888997888rarr










5 Conclusion




Acknowledgment


References
































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of


















5 Conclusion




Acknowledgment


References
































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of


























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of





















of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of
















Documents

Incidence and Predicted Risk Factors of Pressure Ulcers in Surgical